Data reduction
Large number of items \rightarrow smaller number of classes
Mixture model
Population is a “mixture” of subgroups, LCA “unmixes” them
Person-oriented approach
How do people have different patterns, rather than how are the variables related to one another for all people
BIC and LR test are best for choosing the number of classes
AIC and entropy are bad for choosing the correct number of classes
4 continuous indicators, 2 classes
DATA:
FILE IS ex7.9.dat;
VARIABLE:
NAMES ARE y1-y4 x;
USEVARIABLES ARE y1-y4;
CLASSES = c (2);
ANALYSIS:
TYPE = MIXTURE;
PLOT:
TYPE=PLOT3;
SERIES = y1(1) y2(2) y3(3) y4(4);
MODEL RESULTS
Two-Tailed
Estimate S.E. Est./S.E. P-Value
Latent Class 1
Means
Y1 -1.056 0.070 -15.030 0.000
Y2 -1.088 0.067 -16.255 0.000
Y3 -0.943 0.063 -15.050 0.000
Y4 -1.093 0.074 -14.688 0.000
...
Latent Class 2
Means
Y1 1.037 0.070 14.762 0.000
Y2 1.004 0.064 15.682 0.000
Y3 0.865 0.068 12.763 0.000
Y4 0.980 0.060 16.321 0.000
...
GRAPH \rightarrow VIEW GRAPHS \rightarrow ESTIMATED MEANS (Windows only)
Response pattern
DATA: FILE = computer_games.dat;
VARIABLE: NAMES = gender c1-c8;
USEVARIABLES = c1-c8;
CATEGORICAL = c1-c8;
CLASSES = L(3);
ANALYSIS: TYPE = MIXTURE;
PLOT: TYPE = PLOT3;
SERIES = c1(1) c2(2) c3(3) c4(4)
c5(5) c6(6) c7(7) c8(8);
SAVEDATA: FILE = computer_games_3_classes.dat;
SAVE = CPROBABILITIES;
MODEL RESULTS
Two-Tailed
Estimate S.E. Est./S.E. P-Value
Latent Class 1
Thresholds
C1$1 0.555 0.144 3.852 0.000
C2$1 -0.591 0.191 -3.101 0.002
C3$1 -0.097 0.163 -0.593 0.553
C4$1 0.463 0.143 3.244 0.001
C5$1 1.154 0.247 4.680 0.000
C6$1 1.542 0.291 5.290 0.000
C7$1 -0.628 0.152 -4.134 0.000
C8$1 -0.576 0.159 -3.633 0.000
Latent Class 2
Thresholds
C1$1 1.398 0.506 2.761 0.006
C2$1 1.920 0.706 2.717 0.007
C3$1 1.675 0.423 3.961 0.000
C4$1 1.489 0.523 2.850 0.004
C5$1 -0.981 0.406 -2.413 0.016
C6$1 -1.480 0.654 -2.263 0.024
C7$1 0.187 0.357 0.524 0.600
C8$1 0.685 0.334 2.052 0.040
Latent Class 3
Thresholds
C1$1 4.582 0.780 5.872 0.000
C2$1 4.334 0.804 5.388 0.000
C3$1 2.723 0.322 8.455 0.000
C4$1 4.583 0.927 4.947 0.000
C5$1 2.216 0.300 7.391 0.000
C6$1 2.166 0.366 5.924 0.000
C7$1 2.873 0.326 8.817 0.000
C8$1 2.845 0.410 6.937 0.000
...
RESULTS IN PROBABILITY SCALE
Latent Class 1
C1
Category 1 0.635 0.033 19.021 0.000
Category 2 0.365 0.033 10.915 0.000
C2
Category 1 0.356 0.044 8.152 0.000
Category 2 0.644 0.044 14.721 0.000
C3
Category 1 0.476 0.041 11.727 0.000
Category 2 0.524 0.041 12.916 0.000
C4
Category 1 0.614 0.034 18.144 0.000
Category 2 0.386 0.034 11.423 0.000
C5
Category 1 0.760 0.045 16.915 0.000
Category 2 0.240 0.045 5.332 0.000
C6
Category 1 0.824 0.042 19.465 0.000
Category 2 0.176 0.042 4.165 0.000
C7
Category 1 0.348 0.034 10.094 0.000
Category 2 0.652 0.034 18.917 0.000
C8
Category 1 0.360 0.037 9.847 0.000
Category 2 0.640 0.037 17.521 0.000
Latent Class 2
C1
Category 1 0.802 0.080 9.967 0.000
Category 2 0.198 0.080 2.463 0.014
C2
Category 1 0.872 0.079 11.068 0.000
Category 2 0.128 0.079 1.623 0.105
C3
Category 1 0.842 0.056 14.991 0.000
Category 2 0.158 0.056 2.808 0.005
C4
Category 1 0.816 0.078 10.399 0.000
Category 2 0.184 0.078 2.345 0.019
C5
Category 1 0.273 0.081 3.383 0.001
Category 2 0.727 0.081 9.020 0.000
C6
Category 1 0.185 0.099 1.877 0.060
Category 2 0.815 0.099 8.247 0.000
C7
Category 1 0.547 0.088 6.179 0.000
Category 2 0.453 0.088 5.125 0.000
C8
Category 1 0.665 0.074 8.941 0.000
Category 2 0.335 0.074 4.508 0.000
Latent Class 3
C1
Category 1 0.990 0.008 126.531 0.000
Category 2 0.010 0.008 1.295 0.195
C2
Category 1 0.987 0.010 96.062 0.000
Category 2 0.013 0.010 1.259 0.208
C3
Category 1 0.938 0.019 50.383 0.000
Category 2 0.062 0.019 3.309 0.001
C4
Category 1 0.990 0.009 106.680 0.000
Category 2 0.010 0.009 1.090 0.276
C5
Category 1 0.902 0.027 33.919 0.000
Category 2 0.098 0.027 3.699 0.000
C6
Category 1 0.897 0.034 26.596 0.000
Category 2 0.103 0.034 3.049 0.002
C7
Category 1 0.947 0.017 57.362 0.000
Category 2 0.053 0.017 3.242 0.001
C8
Category 1 0.945 0.021 44.386 0.000
Category 2 0.055 0.021 2.580 0.010
GRAPH \rightarrow VIEW GRAPHS \rightarrow ESTIMATED PROBABILITIES (Windows only)
Three class binary